Means for heating a conductive body



E. L. BAILEY 1,873,808 Y MEANS FOR HEATING A coNDUcTIvE BDVY''A FiledMarch S, 1930 2 Sheets-Sheet l Aug. 23, 1932.

ATTORNEYS.

Aug. 23, 1932. f E. L. BAILEY 1,873,808

MEANS FOR HEATING A CONDUCTIVE. BODY Filed March 3. 1930 2 Sheets-Sheet2 INVENTOR fdjar L. az'lqy.

MMM

ATTORNEYS* Patented Aug. 23,' 1932 nnen r.. or nunon'. nomen :murs ronmme a connudrm nonv Application nea :man amo. :um 1ro. 482,187.

` l ous hazard to workmen coming in yproximity a thereto. With the priordevices, the portions of the body which are unfavorably located in thepath of the flux do not develop as high temperatures as fthe other partsof l the body, and when uniform heating is desired such apparatus isunsatisfactory for y this reason.

The main objects of thisinventionare to.

\ providek improved means for heating bodies by electric induction; toprovide means of this kind in. which a non-oscillating circuit ofsubstantially low frequency may be employed for obviatng the danger ofa. high frequency oscillating circuit; to provide an improved heatingdevice in which bodies of regular and irregular shapes may be heateduniformly with equal security.

Further objects of this invention are to provide inductive heatingapparatus sothrough which bodies may be progressively moved withoutinterrupting the apparatus; to provide improved means in heatingapparatus of this kind for heating the ends and other portions of bodieswhich are not advantageously located with respect to the main inductive-flux of the apparatus, which may also be used to concentrate the effectof a local 'luxupon selected parts of a body; and to provide means ofthis kind which do not require electrical connections with thestationary parts of the apparatus, lthereby permitting relative movementof the selectable heating means and the main flux producing'mechanismduring operation.

- 5 An illustrative embodiment of my iivenf 'whichis a apted tolprovidea path for the tion isshown inthe accompanying drawings, inwhich: Y Fig.1 is a view in side elevation of my improved heating apparatus' showinga diagrammatic illustration of a power circuit.

Fig. 2 is a view in left end elevation ofthe heating apparatus shown inFig. 1.

Fig. 3 isa view in vertical section taken `on the line 3-3 of Fig. 2,looking inthe direction indicated by the arrows.

Fig. 4 is a fra entary horizontal sectional view of a col ector coil andheating unit taken on the line of Figi 2, looking in the directionindicated by the arrows.

. Fig. 5-is a view in s'ide elevation of a heating apparatus embodying amodified form of my invention.

Fig. 6 is a view in end elevation of the r apparatus shown in Fi 5. Fig.7 is an enlargedg sectional view taken 65 on the linev 7-7 of Fig.v 5,showing a"well known construction of insulated duplex wire.

In the form shown in Figs. 1, 2, 3 and 4, the heating apparatus includesa coil 1 having substantially twenty turns, each consisting Vof two No.1 B S. gauge wires 2 which are connected in parallel with the terminals3 and 4 ofa generator 5. The wires 2, are wound helically upona framewhich comprises uper an lower pairs 6 and 7, respectively, of 75ongitudinal ribs in which notches 8 are formed for receiving thev wires2 and retaining the convolutions of the coil in spaced relation. Y

The upper pair of ribs or bars 6 are slls- 80 pended `from an overheadstructure (not shown)l by depending bracket arms 9, and the lower pairof ribs 7 rests upon a metal plate 10 which may be supported upon .afloor or other suitable structure. Mounted on 'the 86 pairof ribs 6,externally ofthe coil 1 ita metal `plate l11. The plates 10 and 11,preferably. com rise iron or other suitable metal,

magnetic flux' of the coil. .-f l0` wire 18 are wound, is mounted on theleft end of the platform 15, as viewed in Fig. 1.

This coil is located in a plane substantially normal to the longitudinalaxis of the coil 1. The terminal portions 19 and 20 of the coil 16 areelectrically connected to a pancake coil 21, which is suspendedsubstantially within the collector coil and located at the centralportion thereof, as viewed in.\Fig. 4. There are substantially ten turnsof No. 6 wire in the pancake coil 21.

Electrically connected by conductors 22 and 23, in parallel with thepancake coil 21, is

a second pancake coil 24, which is mounted on a support 25, secured tothe right end of the platform 15 as viewed in Fig. 1. The metal body 16is located on the platform between the pancake coils 21 and 22 which, inthe form shown, are slightly spaced from the ends of the body 16.

In the form shown in Figs. 4 and 5 the solenoid 1 of substantially thesame construction as the solenoid 1, described above, is mounted on aframe having notched longitudinal upper ribs 6, and lower ribs 7.-Mounted on the upper and lower ribs 6 and 7 respectively, are metalplates 1] and 10', for concentrating the magnetic field of the coil,which is created by the current from a generator 5 that is electricallyconnected with the terminal portions of the coil 1 by'` conductors 26and 27.

A laminated metal core 28 preferably formed of superimposed plates ofiron is located at the upper central portion of the interior of the coil1 This core is suspended from the upper plate 11 by U shaped members 29and 30. Resting upon the end portion of the core 28, are coils 31 and32,

each having substantially twenty turns of wire. Pancake coils 33 and 34aredetachably ,connected by couplings 35 and 36, to the coil 31 and 32on the core 28 respectively.

Rails 12 are provided in the lower portion of the coil 1 for supportingwheels 13 'of a carriage 14', on vwhich a metal body 37 may bepositioned in the interior of the coil 1 'and between the coils 33 and34.

In pperation, a low voltage, non-oscillating circuit. having asubstantially low frequency is supplied to the solenoid coils 1 and 1 ineach form of my invention. Satisfactory results have been obtained byusing 200 volts, at 180 cycles; giving a current of 360 amperes. Thiscurrent sets up a magnetic field within the coil, which is induced intothe metal body therein, setting up hysteresi's and eddy currents whichdevelop heat in the metal of the body. The sides, top and bottom of thebody are more advantageously located with respect to the flux of thecoil than the ends thereof, and as a result these portions are heateddirectly by the main flux of the coil to a greater degree than the ends.With the form of my invention shown in Figs. 1 to 4 inclusive, a currentis induced in the collector coil 16 which is fed to the pancake coils 21and 24- These coils cause the ends of the body to heat so that allportions thereof are substantially the same temperature. If it isdesired, the coils 21 and 24 may be placed in close proximity to anyselected portion of the body so as to concentrate the eiect of the fluxof the coil on such selected portion.

With the formof my invention shown in Figs. 5 and 6, the magnetic fluxof the core 28 induces currents into the coils 31 and 32 on therespectively opposite ends thereof. The induced currents in the coils 31and 32 are fed to the pancake coils 33 and 34 respectively, which arelocated in close proximity Both forms of the above heating apparatusy,are particularly adapted for heating automobile bodies. refrigeratorcasings, etc., so as to dryor bake enamel thereon, but it has manydiversified uses. With the apparatus shown in Figs. 1 to 4 inclusive itis possible to progressively convey bodies through the solenoid 1 byemploying several trucks. By the term enamel as herein used in thespecification, and claims, vis meant any and all suitable materials suchas paint, varnish or other similarcoating used to finish the surface ofa metal body.

Although but two specifc'embodiments of this invention have been hereinshown and described. it will be understood that numerous. details of theconstruction shown may be altered or omitted without departing from thespirit of this invention, as defined by the following claims.

I claim:

1. In heating apparatus, an electric circuit. an outer coil electricallyconnected in said circuit for receiving conductive bodies and inducingheat generating current therein, a

collector coil in proximity of said outer coil` and means electricallyconnected with said collector coil for augmenting the effect of saidouter coil on selected parts of said body.

`2. In heating apparatus, p

Y y iesin a substantially central position therein so as to use saidbodiesas a magnetic core for'said coil, an electric circuit connectedwith said' coil for inducing heat generatingcurrents in the-sides ofsaid bodies, and means inductivel)1 energizedb the iiuxof said coil foheating the ends o said bodies.

' the sides of sai 3. In heating apparatus, a coil, a support-in saidcoil for retainin metal bodies in a substantially central position'therein so as to use said `bodies as a magnetic core for said `coil,

an electric circuit connected with vsaid coil for inducing heatgenerating currents in the sides of saidbodics, a collector coil insaidfirst mentioned coil, and a pair of .iiux creating units electricallyconnected with said collector coil, one `located at each end of saidbody.

' 4. In heating apparatus, a coil a support in said coil for retarininmetal substantially central posltion therein sc as to use said bodies asa magnetic core for said coil, an electric circuit connected with saidcoil for inducin bodies, means or collecting a coil a sup rt .y in-saidcoil for 'retaining metal bo Po means for pr 8. In heatin apparatus formetal bodies,

ucm a magnetic field having the capacity of emp oying said metal bodiesas a core,.and an auxiliary flux generating cally connected with saicollecting means for heating selected parts of said bodies.

EDGAR L. BAILEY.v

"asmaI heat generatin currents in 'I some of the flux generated by saidcoil, and a pair of auxiliary units adapted to be energlzed by theenergy collected b said means for heating the ends of said y.

5. In heatin apparatus, an electric circuit i including a coil ada tedto receive a conducytive body for induclng heat generating currentstherein, means externally located with res ct to said coil forconcentrating the mag- ,netlc flux .thereof said'bodyserving as an1nhaving its sides ex osed to.

ternal core and' the main flux thereof, and means in uctively energizedby the fiuxof said coil for heating the ends of said body. Y

' 6. Heating apparatus comprising a solenoid coil an electric circuitfor energizing said coi to produce a magnetic fiel therein, supports`extending lon 'tudinally through sai coil, a carriage shifta ly mountedon said supports for transferring a body through said. magnetic field soas to induce heat generatingcurrents in the sides'thereof,

` and means mounted on said carriage at one end of said body andinductively energized .by said magnetic fluxl for heating saidend.

7. Heating apparatus comprising a solel I noid coil, an` electriccircuit for energizing said coil to produce ama supports extendinglongitudinally through said'coil, a carriage shiftably mounted on saidsupports for l transferring a body through said magneticfield so as toinduce heat generating currents in the .sides"thereof,

gnetic field therein,-

a collector coil o'n'said-carriage in the path ofthe flux of said ield,and an auxiliary flux `generating unit electrically connected with saidcollector coil for ooncentratin the'efect Aof said lflux on a selectedportion o said body.-

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